BASH_REMATCH来匹配任何正则表达式并提供输出。

Question

我试图将输入字符串与regex模式匹配，如下所示：

formatDate(){
 d='[[:digit:]]'
 pattern_a="($d$d$d$d)($d$d)($d$d) ($d$d)($d$d)($d$d)"
 pattern_b="($d$d$d$d)($d$d)($d$d)_($d$d)($d$d)($d$d)"
 pattern_c="($d$d$d$d)($d$d)($d$d):($d$d)($d$d)($d$d)"
 pattern_d="($d$d$d$d)($d$d)($d$d)($d$d)($d$d)($d$d)"
 pattern_e="($d$d$d$d)($d$d)($d$d)($d$d)($d$d)($d$d)($d$d$d)"

 unparsable_date="Unable to parse date!"
 TM="TM"

appName="$1"
actionType="$2"
position="$3"
timestamp="$4"

shopt -s nocasematch
    case "$position" in
       "YYYYMMDD HHMMSS"|"YYYYMMDD_HHMMSS"|"YYYYMMDD:HHMMSS"|"YYYYMMDDHHMMSS"|"YYYYMMDDHHMMSSSSS")
            if [[ $timestamp =~ $pattern_a|$pattern_b|$pattern_c|$pattern_d|$pattern_e ]]; then
               formattedDate=${BASH_REMATCH[1]}${BASH_REMATCH[2]}${BASH_REMATCH[3]}
               formattedTime=${BASH_REMATCH[4]}${BASH_REMATCH[5]}${BASH_REMATCH[6]}
               formattedTimeStamp="$appName$actionType$formattedDate $appName$actionType$TM$formattedTime"
           else
               formattedTimeStamp=$unparsable_date
            fi
       ;;
    esac

 }

如果我的输入与$pattern_a匹配，那么正确填充formattedTimeStamp的值如下所示：

输入- formatDate "appName" "actionType" "YYYYMMDD HHMMSS" "20170426 102300"

输出- appNameactionType20170426 appNameactionTypeTM102300

在与pattern_a以外的任何其他模式匹配的所有其他场景中，代码都不会产生正确的输出，

 appNameactionType appNameactionTypeTM 
"date and time is missing here "

任何帮助都是非常感谢的！

Answer 1

现在，我用for循环.It代替了case语句。

#!/bin/bash
d='[[:digit:]]'
 pattern_a="($d$d$d$d)($d$d)($d$d) ($d$d)($d$d)($d$d)"
 pattern_b="($d$d$d$d)($d$d)($d$d)_($d$d)($d$d)($d$d)"
 pattern_c="($d$d$d$d)($d$d)($d$d):($d$d)($d$d)($d$d)"
 pattern_d="($d$d$d$d)($d$d)($d$d)($d$d)($d$d)($d$d)"
 pattern_e="($d$d$d$d)($d$d)($d$d)($d$d)($d$d)($d$d)($d$d$d)"
 unparsable_date="Unable to parse date!"

 TM="TM"

appName="appName"
actionType="actionType"
position="YYYYMMDD_HHMMSS"
timestamp="20170426_102300"
declare -a arr=( "$pattern_a" "$pattern_b" "$pattern_c" "$pattern_d" "$pattern_e")

for i in "${arr[@]}"
do
   if [[ $timestamp =~ $i ]]; then
    formattedDate=${BASH_REMATCH[1]}${BASH_REMATCH[2]}${BASH_REMATCH[3]}
    formattedTime=${BASH_REMATCH[4]}${BASH_REMATCH[5]}${BASH_REMATCH[6]}
    formattedTimeStamp="$appName$actionType$formattedDate $appName$actionType$TM$formattedTime"
    echo $formattedTimeStamp
    fi
done